1. Field of the Invention
This invention relates generally to electrical devices such as multi-part plug and socket assemblies, switches, feed throughs, test leads, signal wires, and relays, and more specifically relates to electrical devices that incorporate an antenna-effect inhibiting feature to protect signals carried by the device from electromagnetic and/or electrostatic discharge type interference.
The invention relates further to protecting electrical circuits from receiving electromagnetic or electrostatic discharge interference which might be induced in conductors leading to the electrical circuit. More specifically the invention relates to electrical connectors which provide for suppression of electromagnetic or electrostatic discharge interference by means which form part of the connector itself or as an accessory thereto.
This invention applies to the fields of use wherein there is necessity for including an electrical device in a low level signal circuit, e.g. a thermocouple sensor, and provides a new apparatus for eliminating undesired electromagnetically-induced or electrostatic discharge type stray signals.
2. Description of the Prior Art
In the prior art of connectors there are disclosures of the use of ferrite material in the following:
(I) U.S. Patents assigned to AMP Inc: U.S. Pat. Nos. 4,699,590, 4,359,620, 3,789,263, U.S. Pat. No. Re 29,258, U.S. Pat. Nos. 3,735,705, 3,987,380, 4,936,800. PA0 (II) U.S. Patent assigned to The Whitaker Corp: U.S. Pat. No. 5,219,305. PA0 (III) U.S. Patent William Baird Fritz U.S. Pat. No. 3,743,978 PA0 (IV) U.S. Patent assigned to Stanford Research Institute and Amplex Corporation: U.S. Pat. No. 3,533,948. PA0 (V) Un-examined Japanese Patent Application, AMP Inc., 90-032246/05 JO 1279-584-A discloses an electrical connector which has a noise filter with a ferrite head fitted to a terminal lead formed by a central conductor of a feed-through capacitor. PA0 (VI) German Patent assigned to AMP Inc., Auslegeschrift No. 2,058,419 discloses a method for the manufacture of a high frequency filter from a ferrite tube, which is in the form of a highly compressed tube and which is bonded on its outer surface with a covering of dielectric material, the layer of dielectric material carrying an electrode in the form of a metallic outer sleeve, and a further electrode is provided in similar manner on the inside of the ferrite tube, characterised in that the covering (6) of dielectric material is laid down directly onto the outer surface of the ferrite tube (5) by electrophoresis.